Ummm you don't have a litter box anywhere near the door do you? LOL ~Not to be gross, but we had some huge slugs in LA that would get into the back mudroom and go straight for covered the litter box ewww! My poor cat thought it was being invaded by aliens.

Slugs are attracted to moisture which is why they go under the sinks. Check the weather stripping under the doors (that was our problem) to try and see where they are getting in. You could try ammonia and water and squirt the slugs, it burns them. Or try the beer traps.

Here is a link that might be useful: slug killing

They say they won't cross copper either so if you can find some copper tape and put it around the bottom of the walls outside maybe it would keep them out. I would see if you have a water leak or something attracting them into the house. They usually go to moist places.

Put out a bowl that is kinda low, and fill it with beer. The slugs are attracted to the beer and fall in the bowl, and drown, this is the best slug remedy that I know of. Barbra,